Sleep Study Questions
1) We discussed 3 possible functions of sleep in general; know those.
• 1)Energy Conservation, Restoration, Memory
• Repair and restoration; growth hormone secreted, wound healing increased
• Learning & memory consolidation
• All of these may be true.
• Sleep is useful for conserving energy while an animal is inactive.
• Body temperature drops and metabolism slows down.
• The brain is inactive and uses less energy.
• It also makes the animal inconspicuous.
• Sleep may also help to recalibrate the senses.
• Gives neurons a chance to rebuild
• Neurotransmitter production cant keep up with continuous activity
• Monoamine neurotransmitters are depleted
• Essential for wakefulness, mood, and attention
2) We also discussed possible functions of REM sleep; know those.
3) What are the different stages of sleep? In general, what is brain activity like in those
stages? In what order do humans move thru these stages during a night of sleep? What
do heart rate, breathing, blood pressure and temperature do during the different stages
4) What is “paradoxical” about REM sleep? What neurotransmitters are involved? How is it
related to dreams?
5) When dreaming, what brain areas are very active, and which ones are inactive? What is
the functional consequence of that (for example, the prefrontal cortex being inactive
leads to poor memory and logic in dreams)? What are PGO waves?
6) Know/understand some common sleep disorders: insomnia, narcolepsy, sleep apnea,
periodic limb movement disorder (restless leg syndrome), REM behavior disorder, night
terrors, sleep walking, sleep talking.
7) As we age, what changes about overall sleep and the amount of time spent in REM
sleep, and what happens to the incidence of sleep disorders?
Sensory Systems Study Questions:
1) What are the names of the receptors for each sensory system and where are they
o Eye (retina) photoreceptors (rods and cones)
o Ear (cochlea) hair cells
o Nose (olfactory epithelium) olfactory receptor cells
o Mouth (tongue) taste receptor cells
o Skin mechanoreceptors, nociceptors, thermoreceptors, chemoreceptors
2) What are some differences between rods and cones?
o Abundant in the periphery
o Best for dim light
o See black/white o Good sensitivity; not great for visual acuity
o Abundant in the fovea
o Best for bright light
o See color
o Good for visual acuity; not great sensitivity
3) What is the speech banana?
o The speech banana is called such due to its shape. When the sounds of speech
or phonemes of all the world’s languages are charted in a diagram with one axis containing
decibel levels (dB) and the other axis containing the frequency (Hertz or Hz), the shape is
that of a banana. Generally, the graph known as an audiogram is charted with frequency
levels (Hz) on the X-axis and the decibel levels (dB) on the Y-axis.
o However, normal human hearing can occur with sounds outside of the Speech Banana.
These sounds include ambient natural sounds such as a rustling of leaves in the wind or
birds chirping. Man made sounds outside of the Speech Banana can include music and
mechanical noises (i.e., automobiles, lawn mowers).
•What are important factors in determining the range of stimuli a species can respond to (ie,
the frequencies of sounds, the wavelengths of light, etc)? In what other ways do different
species differ from each other in terms of sensory systems?
o Transduction determines range of stimuli
o We can’t transduce all energy
o Can only see small portion of electromagnetic radation (visual light)
o Can only hear a small range of frequencies
o Differs between species depending on
What they need to be sensitive to (predators; pretyetc)
Structure of receptor organ and receptor cells
Species differences also in terms of sensitivitiy and discrimination
Mice discriminate more odors than we do
Dogs are more sensitive to odors than we are
•What is transduction? What type of cells are responsible for transduction? How does
transduction occur in hair cells and in photoreceptors?
o Transforming physical energy into the world into electrical energy in our bodies
o Receptor cells
o Hair cells:
o sound waves travel thru outer and middle ear to cochlea causing a wave
In the fluid within the cochlea
o Fluid movement causes stereocilia to pivot back and forth
o Pivoting stretches tip links, which are connected to K+ channels
o K+ channels are opened and K+ enters cell, depolarizing it
o •VG Ca++ channels open neurotransmitter is released
o NT depolarizes axon of auditory nerve action potentials sent to brain!
o Photoreceptors: o •Without light, receptors inhibit bipolar cells (the “dark current”)
o •Light hyperpolarizes photoreceptor cells
o •Receptors stop NT release
o •Bipolar cells are disinhibited
o •Bipolar cells stimulate ganglion cells
–By releasing an excitatory NT
o •AP down optic nerve
•What are labeled line coding and cross fiber patterning? What are examples of each from
different sensory systems?
o •Labeled line: the specific axon carrying the information provides useful info in
understanding the stimulus
o –Frequency of very high frequency sounds (esp. if quiet)
o –Primary taste
o •Cross fiber patterning: the pattern of activation across many receptors/axons gives the
brain useful coding information
o –Color (next)
most light is reflected light
when light hits an object, some is absorbed some reflected
more absorbed darker looks
wavelengths that are reflected enter our eye perception of
o –Discrimination w/in primary taste
o –Sound frequency (especially if low-ish frequency or well above threshold)
•What is the rate law?
o Rate of action potentials directly related to intensity of stimulus
•What is the role of the (1) brainstem and spinal cord, (2) thalamus, and (3) cortex, in
processing sensory stimuli?
o •Brainstem/spinal cord
•Conjugate lateral gaze
•Chewing & salivating
•Each sensory system gets its own thalamic nucleus
o –Conscious perception & high level evaluation
•Each sensory system gets its own primary sensory cortex
o –Organization: •Tonotopic, somatotopic, retinotopic
•What do the terms somatotopic, tonotopic, and retinotopic mean?
o Somatotopy is the point-for-point correspondence of an area of the body to a specific
point on the central nervous system. Typically, the area of the body corresponds to a
point on the primary somatosensory cortex
o tonotopy (from Greek tono- and topos = place) is the spatial arrangement of where
sounds of different frequency are processed in the brain.
o Retinotopy describes the spatial organization of the neuronal responses to visual
stimuli. In many locations within the brain, adjacent neurons have receptive
fields that include slightly different, but overlapping portions of the visual field.
•What is the trichromatic theory of color vision? What are after images and why do they
o •three kinds of receptors for human color vision (color cones)
o • each type of cone is maximally sensitive to a different set of wavelengths
(short, medium and long wavelengths)
o • color is perceived through the relative rates of response of each cones any
response by any one cone is ambiguous (CNS must process relative activity
across all cones)…this is why we don’t see color well in the dark… perception of
color relies on cross-fiber patterning and only 1 type of photoreceptor is active in
the dark (rods)
o •Pigment in blue cones is selectively adapted or fatigued
o •Look at white or gray surface…only unadapted cone pigments are active
(green and red)
o •Combo of green and red perceive yellow
•How are sensation and perception different from each other? Know examples from the
auditory and visual system, and from aspects of pain perception.
o •Amplitude and loudness
o •Frequency and pitch
o •Visual system in general!
What are some possible functions of sleep? Why does sleep length vary between different
o Conservation of energy
o Repair and restoration; growth hormone secreted, wound healing increased
o Learning & memory consolidation
o All of these may be true.
o Sleep is useful for conserving energy while an animal is inactive.
Body temperature drops and metabolism slows down.
The brain is inactive and uses less energy.
o It also makes the animal inconspicuous.
o Sleep may also help to recalibrate the senses.
o Sleep is restorative o Gives neurons a chance to rebuild
o Neurotransmitter production cant keep up with continuous activity
Monoamine neurotransmitters are depleted
Essential for wakefulness, mood, and attention
o What are the three major types of sleep? How can you measure them?
o Light NREM sleep (stage 1 and 2): the sleeper is easily awakened and brain
waves are still relatively fast, albeit slower than wakefulness.
o Slow wave (deep) NREM sleep (stage 3 and 4): the sleeper is in deep sleep and is
difficult to awake. When woken from deep sleep, the person usually feels groggy.
o REM (rapid eye movement) sleep: also called paradoxical sleep because the brain
waves are fast but the body is relaxed and the person doesn’t wake up easily. It is
accompanied by rapid back and forth eye movements.
o Show electroencephalogram (EEG) waves; NREM=nonREM
o A polysomnograph includes records of EEG, eye movements, and sometimes
other data, such as muscle tension or head movements
o Which stage of sleep is associated with vivid dreams?
o More vivid dreams are probably from REM
o How is sleep important for memories?
o The brain “replays” and “practices” events repeatedly to stamp them into
o Why don't you move around while you're asleep?
o During REM sleep, the forebrain is active, including the motor cortex.
o Why don’t you flail all over your bed as you sleep?
o Remember the reticular formation that’s responsible for arousal?
Part of the reticular formation* causes atonia during sleep.
They hyperpolarize motor neurons to keep them from firing.
o Damage to the pons can result in movement while asleep.
o What neurotransmitters are depleted during sleep deprivation? What are some of
the symptoms of sleep deprivation? How might these be related?
o Monoamine neurotransmitters are depleted. (Which are these?)
o They are essential for wakefulness, mood, and attention.
5HT = Serotonin
DA = Dopamine
NE = Norepinephrine
His = Histamine
o Deprivation results in poor reaction time, memory loss, mood imbalance, and
Emotion and Agression
o •What is the James-Lange theory of emotion? What predictions does it make? What
research supports this hypothesis?
o •James-Lange theory